A mid-career play of Tennessee Williams, The Night of the Iguana deals with the travails of Reverend T. Lawrence Shannon, a 35-year-old former clergyman who has been defrocked due to a sexual relationship with a young woman and a heretical sermon. As the play begins, he's conducting a group of teachers from a Baptist women's college on a bus tour through Mexico.

Shannon is an alcoholic who has already had more than his share of nervous breakdowns. He's right in the midst of another as he stops the bus at the dilapidated hotel of his old friend, the middle-aged Maxine Faulk, for a badly needed rest. Shortly after his arrival, Hannah Jelkes, a rather ethereal woman of roughly Shannon's age, also checks into the hotel. She is with her frail, elderly grandfather Nonno, a poet working on the final poem of his life.

Despite the desperate nature of his circumstances, Shannon finds himself the reluctant love/lust object of Maxine and Charlotte Goodall, 18-year-old girls on his tour. Yet he also finds himself drawn into an deep relationship with the chaste, decorous, Hannah.

In the latter part of Act 2, Shannon has again lost control and begun cutting himself with a crucifix. Maxine, accustomed to these episodes, has her houseboys truss him up in a hammock until he calms down. During his confinement, Hannah engages him in conversation, partly as a type of palliative and calming care, but partly also because she feels that they are kindred spirits who can help each other.

After he is freed, he makes himself a drink but tosses it away at Hannah's request. Later, Hannah fervently asks Shannon to free an iguana who has been trapped up by the houseboys. He initially resists. As he becomes aware of how painful this is to her, complies with her wish. Hannah has helped him to begin seeing beyond his own pain and start to empathize with the suffering of others.